>From d52213a33a71142134555793583b726501827827 Mon Sep 17 00:00:00 2001
From: Philip Rakity <prakity@xxxxxxxxxxx>
Date: Sun, 21 Nov 2010 11:08:21 -0800
Subject: [PATCH] [PATCH] sdhci: resubmit 8 bit support based on feedback from list
a) QUIRK removed for 8 bit support since platform issue - not quirk
b) platform Flag defined for sdhci-pxa.c and plat-pxa
c) comments added to sdhci.c on usage
Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
comments from previous submission
We now:
* check for a v3 controller before setting 8-bit bus width
* offer a callback for platform code to switch to 8-bit mode, which
allows non-v3 controllers to support it
* introduce a quirk to specify that the board designers have indeed
brought out all the pins for 8-bit to the slot.
We were previously relying only on whether the controller supported
8-bit, which doesn't tell us anything about the pin configuration in
the board design.
Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
Tested-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
---
arch/arm/plat-pxa/include/plat/sdhci.h | 3 ++
drivers/mmc/host/sdhci-pxa.c | 4 ++
drivers/mmc/host/sdhci.c | 49 ++++++++++++++++++++++++--------
drivers/mmc/host/sdhci.h | 4 ++-
4 files changed, 47 insertions(+), 13 deletions(-)
diff --git a/arch/arm/plat-pxa/include/plat/sdhci.h b/arch/arm/plat-pxa/include/plat/sdhci.h
index e49c5b6..e85b58f 100644
--- a/arch/arm/plat-pxa/include/plat/sdhci.h
+++ b/arch/arm/plat-pxa/include/plat/sdhci.h
@@ -17,6 +17,9 @@
/* Require clock free running */
#define PXA_FLAG_DISABLE_CLOCK_GATING (1<<0)
+/* board design supports 8 bit data on SD/SDIO BUS */
+#define PXA_FLAG_SD_8_BIT_CAPABLE_SLOT (1<<2)
+
/*
* struct pxa_sdhci_platdata() - Platform device data for PXA SDHCI
* @max_speed: the maximum speed supported
diff --git a/drivers/mmc/host/sdhci-pxa.c b/drivers/mmc/host/sdhci-pxa.c
index fc406ac..f609f4a 100644
--- a/drivers/mmc/host/sdhci-pxa.c
+++ b/drivers/mmc/host/sdhci-pxa.c
@@ -141,6 +141,10 @@ static int __devinit sdhci_pxa_probe(struct platform_device *pdev)
if (pdata->quirks)
host->quirks |= pdata->quirks;
+ /* if slot design supports 8 bit data - indicate this */
+ if (pdata->flags & PXA_FLAG_SD_8_BIT_CAPABLE_SLOT)
+ host->mmc->caps |= MMC_CAP_8_BIT_DATA;
+
ret = sdhci_add_host(host);
if (ret) {
dev_err(&pdev->dev, "failed to add host\n");
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 154cbf8..03c801b 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1185,17 +1185,31 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (host->ops->platform_send_init_74_clocks)
host->ops->platform_send_init_74_clocks(host, ios->power_mode);
- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
-
- if (ios->bus_width == MMC_BUS_WIDTH_8)
- ctrl |= SDHCI_CTRL_8BITBUS;
- else
- ctrl &= ~SDHCI_CTRL_8BITBUS;
+ /*
+ * If your platform has 8-bit width support but is not a v3 controller,
+ * or if it requires special setup code, you should implement that in
+ * platform_8bit_width().
+ */
+ if (host->ops->platform_8bit_width)
+ host->ops->platform_8bit_width(host, ios->bus_width);
+ else {
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ if (ios->bus_width == MMC_BUS_WIDTH_8) {
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ if (host->version >= SDHCI_SPEC_300)
+ ctrl |= SDHCI_CTRL_8BITBUS;
+ } else {
+ if (host->version >= SDHCI_SPEC_300)
+ ctrl &= ~SDHCI_CTRL_8BITBUS;
+ if (ios->bus_width == MMC_BUS_WIDTH_4)
+ ctrl |= SDHCI_CTRL_4BITBUS;
+ else
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ }
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ }
- if (ios->bus_width == MMC_BUS_WIDTH_4)
- ctrl |= SDHCI_CTRL_4BITBUS;
- else
- ctrl &= ~SDHCI_CTRL_4BITBUS;
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
if ((ios->timing == MMC_TIMING_SD_HS ||
ios->timing == MMC_TIMING_MMC_HS)
@@ -1855,11 +1869,22 @@ int sdhci_add_host(struct sdhci_host *host)
mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
else
mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
+
mmc->f_max = host->max_clk;
mmc->caps |= MMC_CAP_SDIO_IRQ;
- if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
- mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA;
+ /*
+ * A controller may support 8-bit width, but the board itself
+ * might not have the pins brought out. So, boards that support
+ * 8-bit width should set the MMC_CAP_8_BIT_DATA and we won't assume
+ * that devices without the quirk can use 8-bit width.
+ *
+ * set mmc->caps |= MMC_CAP_8_BIT_DATA in platfrom code
+ * before call for_add_host to enable 8 bit support
+ */
+ if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA)) {
+ mmc->caps |= MMC_CAP_4_BIT_DATA;
+ }
if (caps & SDHCI_CAN_DO_HISPD)
mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d52a716..ff18eaa 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -76,7 +76,7 @@
#define SDHCI_CTRL_ADMA1 0x08
#define SDHCI_CTRL_ADMA32 0x10
#define SDHCI_CTRL_ADMA64 0x18
-#define SDHCI_CTRL_8BITBUS 0x20
+#define SDHCI_CTRL_8BITBUS 0x20
#define SDHCI_POWER_CONTROL 0x29
#define SDHCI_POWER_ON 0x01
@@ -215,6 +215,8 @@ struct sdhci_ops {
unsigned int (*get_max_clock)(struct sdhci_host *host);
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
+ int (*platform_8bit_width)(struct sdhci_host *host,
+ int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
u8 power_mode);
unsigned int (*get_ro)(struct sdhci_host *host);
--
1.6.0.4
On Nov 20, 2010, at 10:24 AM, Chris Ball wrote:
> Hi,
>
> On Sat, Nov 20, 2010 at 01:35:53PM +0100, Wolfram Sang wrote:
>> I know it's too late, but...
>
> It's late, but it's not too late. I'd like to send a fix for MMC cards
> to Linus within the next week. If we decide to make some small changes
> here and can do it quickly, that should be fine.
>
>> What does the platform_-prefix of the callback indicate?
>
> That it's a hook for code (whether that's a -pltfm driver or an SDHCI
> driver) that knows more about the board-level setup to implement.
>
>>> * introduce a quirk to specify that the board designers have indeed
>>> brought out all the pins for 8-bit to the slot.
>>
>> This is not a quirk, this is platform_data, no?
>
> Yes, I agree that platform code would be more correct than the quirk.
>
> Thanks,
>
> --
> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
> One Laptop Per Child
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